:root{--bg:#f6f8fb;--surface:#fff;--surface2:#f9fbff;--ink:#17212b;--muted:#667585;--brand:#2563eb;--brand2:#0ea5e9;--accent:#16a34a;--danger:#dc2626;--warn:#b45309;--line:#e5eaf1;--shadow:0 10px 30px rgba(15,23,42,.08)}*{box-sizing:border-box}body{margin:0;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","Microsoft YaHei",sans-serif;background:linear-gradient(180deg,#ffffff 0,#f6f8fb 360px);color:var(--ink)}header{position:sticky;top:0;z-index:5;display:flex;align-items:center;justify-content:space-between;gap:18px;padding:14px 5vw;background:rgba(255,255,255,.92);border-bottom:1px solid var(--line);backdrop-filter:blur(14px)}.brand{font-weight:850;color:var(--ink);text-decoration:none}.brand:before{content:"生物";display:inline-block;margin-right:8px;color:var(--brand);font-weight:900}nav{display:flex;flex-wrap:wrap;gap:8px}nav a,a.button{color:#334155;text-decoration:none;font-weight:650;border:1px solid var(--line);border-radius:8px;padding:8px 11px;background:#fff}nav a:hover,a.button:hover{border-color:#bfdbfe;color:var(--brand);background:#eff6ff}main{max-width:1120px;margin:0 auto;padding:28px 18px 52px}.hero{padding:30px 0}.hero h1{margin:0 0 10px;font-size:36px;line-height:1.16;color:#0f172a}.hero p{max-width:760px;color:var(--muted);font-size:17px}.panel{background:var(--surface);border:1px solid var(--line);border-radius:8px;padding:22px;margin:16px 0;box-shadow:var(--shadow)}.narrow{max-width:540px;margin:34px auto}.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(230px,1fr));gap:14px}.card{display:flex;flex-direction:column;gap:10px;min-height:126px;padding:18px;background:var(--surface);border:1px solid var(--line);border-radius:8px;text-decoration:none;color:var(--ink);box-shadow:0 6px 22px rgba(15,23,42,.05)}.card:hover{border-color:#bfdbfe;box-shadow:var(--shadow);transform:translateY(-1px)}.card b{font-size:18px}.card span,.muted{color:var(--muted)}h1,h2,h3{letter-spacing:.1px}label{display:flex;flex-direction:column;gap:7px;margin:11px 0;font-weight:650;color:#243244}input,select,textarea{width:100%;border:1px solid #d8e0ea;border-radius:8px;padding:12px;background:#fff;color:var(--ink);font:inherit;outline:none}input:focus,select:focus,textarea:focus{border-color:#93c5fd;box-shadow:0 0 0 3px rgba(37,99,235,.12)}textarea{min-height:126px}button,.button{display:inline-block;border:0;border-radius:8px;padding:11px 18px;background:var(--brand);color:#fff!important;cursor:pointer;font-weight:800}button:hover,.button:hover{background:#1d4ed8;color:#fff!important}table{width:100%;border-collapse:collapse;background:#fff;border:1px solid var(--line);border-radius:8px;overflow:hidden}th,td{border-bottom:1px solid var(--line);padding:11px;text-align:left;vertical-align:top}th{background:#f1f5f9;color:#334155}.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(190px,1fr));gap:12px}.stats{display:grid;grid-template-columns:repeat(auto-fit,minmax(138px,1fr));gap:12px}.stats div{background:#fff;border:1px solid var(--line);border-radius:8px;padding:16px;box-shadow:0 6px 18px rgba(15,23,42,.04)}.stats b{display:block;font-size:28px;color:var(--brand)}.error{background:#fef2f2;color:#991b1b;border:1px solid #fecaca;padding:11px;border-radius:8px}.success{background:#f0fdf4;color:#166534;border:1px solid #bbf7d0;padding:11px;border-radius:8px}.badge{display:inline-block;background:#eff6ff;border:1px solid #bfdbfe;border-radius:999px;padding:5px 11px;margin:4px;color:#1d4ed8}.diagram-card{background:#fff;border:1px solid var(--line);border-radius:8px;padding:18px;box-shadow:var(--shadow)}.diagram-svg{width:100%;height:auto;background:#f8fbff;border:1px solid #dbeafe;border-radius:8px}.node rect{fill:#e0f2fe;stroke:#0284c7;stroke-width:2}.node-title{font-weight:850;fill:#0f172a}.node-desc{font-size:11px;fill:#475569}.edge-label{font-size:12px;fill:#0369a1}.steps{display:grid;gap:9px;margin-top:13px}.step{background:#eff6ff;color:#1e293b!important;text-align:left}.step span{display:block;font-weight:400;margin-top:4px;color:var(--muted)}.hint-step{display:none;padding:13px;background:#f8fafc;border:1px solid var(--line);border-radius:8px}.hint-step.active{display:block}.safety{color:#854d0e;background:#fffbeb;border:1px solid #fde68a;padding:10px;border-radius:8px}footer{text-align:center;color:var(--muted);padding:22px;border-top:1px solid var(--line);background:#fff}@media(max-width:720px){header{align-items:flex-start;flex-direction:column;padding:12px 16px}.hero{padding:20px 0}.hero h1{font-size:28px}main{padding:18px 12px}.cards{grid-template-columns:1fr}nav{width:100%;overflow-x:auto;flex-wrap:nowrap;padding-bottom:2px}nav a{white-space:nowrap;padding:7px 10px}.panel{padding:16px}th,td{padding:9px;font-size:14px}}
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.login-hero{display:grid;grid-template-columns:minmax(0,1fr) 260px;gap:24px;align-items:center;padding:34px 0}.earth-wrap{display:flex;justify-content:center}.earth{position:relative;width:190px;height:190px;border-radius:50%;background:radial-gradient(circle at 35% 30%,#dff7ff 0,#7dd3fc 28%,#2563eb 66%,#1e3a8a 100%);box-shadow:0 18px 50px rgba(37,99,235,.25);animation:floatEarth 4s ease-in-out infinite}.earth:before{content:"";position:absolute;inset:18px;border-radius:50%;border:1px solid rgba(255,255,255,.55);transform:rotateX(68deg)}.orbit{position:absolute;left:50%;top:50%;width:230px;height:70px;border:1px solid rgba(37,99,235,.28);border-radius:50%;transform:translate(-50%,-50%) rotate(-18deg)}.orbit-two{transform:translate(-50%,-50%) rotate(32deg);width:215px}.land{position:absolute;background:#bbf7d0;border-radius:50% 45% 55% 40%;opacity:.9}.land-one{width:54px;height:34px;left:42px;top:48px;transform:rotate(-20deg)}.land-two{width:42px;height:60px;right:42px;top:76px;transform:rotate(25deg)}.land-three{width:54px;height:26px;left:72px;bottom:42px;transform:rotate(12deg)}@keyframes floatEarth{0%,100%{transform:translateY(0) rotate(-2deg)}50%{transform:translateY(-8px) rotate(2deg)}}@media(max-width:720px){.login-hero{grid-template-columns:1fr;text-align:left;padding:18px 0}.earth{width:130px;height:130px}.orbit{width:165px;height:52px}.earth-wrap{justify-content:flex-start}}
.study-shell{max-width:900px;margin:0 auto}.study-head{display:flex;align-items:flex-end;justify-content:space-between;gap:16px;margin:8px 0 14px}.study-head h1{margin:0 0 8px;font-size:32px}.progress-box{min-width:180px;background:#fff;border:1px solid var(--line);border-radius:8px;padding:14px;text-align:center;box-shadow:0 8px 24px rgba(15,23,42,.06)}.progress-box b{display:block;font-size:30px;color:var(--brand)}.progress-box span{display:block;color:var(--muted);font-size:14px}.progress-line{height:12px;background:#eaf0f7;border-radius:999px;overflow:hidden;margin:12px 0 18px}.progress-line span{display:block;height:100%;background:linear-gradient(90deg,var(--brand),var(--brand2));border-radius:999px}.study-card{background:#fff;border:1px solid var(--line);border-radius:8px;padding:22px;box-shadow:var(--shadow)}.card-main{display:grid;grid-template-columns:minmax(0,1fr) 300px;gap:22px;align-items:center}.card-copy h2{font-size:28px;margin:10px 0}.card-copy p{font-size:18px;line-height:1.75;color:#334155}.card-image{background:#f8fbff;border:1px solid #dbeafe;border-radius:8px;padding:10px}.card-image svg{display:block;width:100%;height:auto}.card-image text{font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","Microsoft YaHei",sans-serif;font-weight:800;fill:#17212b}.answer-form{margin-top:18px;border-top:1px solid var(--line);padding-top:18px}.answer-form h3{font-size:22px;margin:0 0 14px}.answer-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin-bottom:16px}.answer-option{margin:0;display:block;cursor:pointer}.answer-option input{position:absolute;opacity:0;width:1px;height:1px}.answer-option span{display:flex;gap:10px;align-items:flex-start;min-height:58px;border:1px solid #d8e0ea;border-radius:8px;padding:14px;background:#fff;color:#1f2937;font-weight:700}.answer-option span b{display:inline-grid;place-items:center;flex:0 0 28px;height:28px;border-radius:50%;background:#eff6ff;color:var(--brand)}.answer-option input:checked+span{border-color:#2563eb;background:#eff6ff;box-shadow:0 0 0 3px rgba(37,99,235,.12)}.finish-panel{text-align:center}.finish-panel h2{font-size:30px;margin-top:0}@media(max-width:720px){.study-head{display:block}.study-head h1{font-size:28px}.progress-box{text-align:left;margin-top:12px}.card-main{grid-template-columns:1fr}.study-card{padding:16px}.card-copy h2{font-size:24px}.card-copy p{font-size:16px}.answer-grid{grid-template-columns:1fr}.answer-form button{width:100%;font-size:17px}.card-image{padding:6px}}

.login-page{background:#020817;color:#eaf6ff;overflow:hidden}.login-page main{max-width:none;margin:0;padding:0}.login-screen{position:relative;min-height:100vh;display:grid;grid-template-columns:minmax(0,1fr) 390px;align-items:center;gap:34px;padding:32px clamp(22px,5vw,72px);background:radial-gradient(circle at 45% 36%,rgba(14,165,233,.22),transparent 28%),radial-gradient(circle at 20% 80%,rgba(37,99,235,.18),transparent 28%),linear-gradient(135deg,#020617 0,#061329 48%,#020817 100%);overflow:hidden}.space-scene{position:relative;min-height:560px}.star-layer{position:absolute;inset:0;background-image:radial-gradient(#e0f2fe 1px,transparent 1px),radial-gradient(rgba(125,211,252,.65) 1px,transparent 1px);background-size:86px 86px,132px 132px;opacity:.55;animation:starDrift 16s linear infinite}.star-two{opacity:.35;background-size:148px 148px,210px 210px;animation-duration:26s}.digital-earth{position:absolute;left:50%;top:50%;width:min(46vw,430px);height:min(46vw,430px);min-width:280px;min-height:280px;transform:translate(-50%,-50%);border-radius:50%;background:radial-gradient(circle at 42% 32%,#7dd3fc 0,#0ea5e9 22%,#075985 48%,#02152f 72%,#010814 100%);box-shadow:0 0 44px rgba(14,165,233,.75),inset -28px -34px 70px rgba(0,0,0,.62);animation:earthFloat 5s ease-in-out infinite}.digital-earth:before{content:"";position:absolute;inset:12%;border-radius:50%;background:linear-gradient(140deg,transparent 8%,rgba(186,230,253,.9) 9%,transparent 11%,transparent 24%,rgba(186,230,253,.75) 25%,transparent 27%,transparent 45%,rgba(186,230,253,.65) 46%,transparent 48%),linear-gradient(35deg,transparent 16%,rgba(56,189,248,.55) 17%,transparent 19%,transparent 34%,rgba(56,189,248,.55) 35%,transparent 38%,transparent 60%,rgba(56,189,248,.45) 61%,transparent 64%);filter:drop-shadow(0 0 8px rgba(125,211,252,.9));opacity:.8}.digital-earth:after{content:"";position:absolute;inset:-18px;border-radius:50%;border:1px solid rgba(125,211,252,.24);box-shadow:0 0 34px rgba(14,165,233,.35)}.earth-glow{position:absolute;inset:-20%;border-radius:50%;background:radial-gradient(circle,rgba(56,189,248,.18),transparent 64%)}.earth-line{position:absolute;left:50%;top:50%;width:128%;height:28%;border:1px solid rgba(147,197,253,.38);border-radius:50%;transform:translate(-50%,-50%) rotate(-16deg);box-shadow:0 0 16px rgba(56,189,248,.22)}.line-b{width:116%;height:34%;transform:translate(-50%,-50%) rotate(42deg)}.line-c{width:112%;height:25%;transform:translate(-50%,-50%) rotate(82deg)}.earth-land{position:absolute;background:rgba(165,243,252,.5);border:1px solid rgba(224,242,254,.8);box-shadow:0 0 14px rgba(56,189,248,.85);border-radius:48% 42% 54% 38%}.land-a{width:24%;height:16%;left:26%;top:24%;transform:rotate(-22deg)}.land-b{width:18%;height:28%;right:25%;top:36%;transform:rotate(22deg)}.land-c{width:28%;height:13%;left:34%;bottom:25%;transform:rotate(12deg)}.login-card{position:relative;z-index:2;width:100%;background:rgba(255,255,255,.94);color:#142033;border:1px solid rgba(191,219,254,.55);border-radius:14px;padding:26px;box-shadow:0 24px 70px rgba(0,0,0,.36);backdrop-filter:blur(18px)}.login-title span{display:inline-block;color:#2563eb;font-weight:900;margin-bottom:6px}.login-title h1{margin:0;font-size:34px;line-height:1.05}.login-title p{margin:10px 0 18px;color:#64748b}.login-card label{margin:12px 0}.login-card input{height:46px}.login-card button{width:100%;height:46px;margin-top:6px}.login-note{text-align:center;margin:12px 0 0;color:#64748b;font-size:14px}@keyframes earthFloat{0%,100%{transform:translate(-50%,-50%) translateY(0) rotate(-2deg)}50%{transform:translate(-50%,-50%) translateY(-10px) rotate(2deg)}}@keyframes starDrift{from{transform:translateY(0)}to{transform:translateY(40px)}}@media(max-width:760px){.login-page{overflow:auto}.login-screen{min-height:100svh;grid-template-columns:1fr;gap:10px;padding:18px 16px 22px}.space-scene{min-height:300px}.digital-earth{width:240px;height:240px;min-width:240px;min-height:240px}.login-card{padding:20px;border-radius:12px}.login-title h1{font-size:28px}.login-title p{margin-bottom:12px}.login-card label{margin:9px 0}.login-card input,.login-card button{height:44px}}
.ask-fab{position:fixed;right:22px;bottom:24px;z-index:20;width:58px;height:58px;border-radius:999px;padding:0;box-shadow:0 14px 36px rgba(37,99,235,.32)}.ask-drawer{position:fixed;inset:0;z-index:30;display:none;background:rgba(15,23,42,.18)}.ask-drawer.open{display:block}.ask-panel{position:absolute;right:22px;bottom:92px;width:min(390px,calc(100vw - 28px));background:#fff;border:1px solid var(--line);border-radius:12px;box-shadow:0 24px 70px rgba(15,23,42,.22);overflow:hidden}.ask-panel-head{display:flex;align-items:flex-start;justify-content:space-between;gap:12px;padding:16px 16px 12px;border-bottom:1px solid var(--line);background:#f8fbff}.ask-panel-head b{display:block;font-size:18px;color:#0f172a}.ask-panel-head span{display:block;margin-top:4px;font-size:13px;color:#64748b}.ask-close{width:32px;height:32px;border-radius:8px;padding:0;background:#fff!important;color:#334155!important;border:1px solid var(--line)}#askFloatForm{padding:14px 16px 16px}#askFloatForm textarea{min-height:112px;resize:vertical}#askFloatForm button{width:100%;margin-top:10px}.ask-answer{margin:0 16px 16px;padding:12px;border-radius:8px;background:#f8fafc;border:1px solid var(--line);color:#1f2937;line-height:1.65;white-space:pre-wrap}.ask-answer b{display:block;margin-bottom:4px;color:#0f172a}.ask-answer p{margin:0}.ask-answer span{display:block;margin-top:8px;color:#64748b;font-size:13px}.ask-answer.loading{color:#475569}.ask-answer.error{background:#fef2f2;color:#991b1b;border-color:#fecaca}@media(max-width:720px){.ask-fab{right:16px;bottom:16px;width:56px;height:56px}.ask-panel{left:10px;right:10px;bottom:10px;width:auto;border-radius:12px}.ask-panel-head{padding:14px}.ask-drawer.open{background:rgba(15,23,42,.3)}#askFloatForm textarea{min-height:130px}}
.principle{display:flex;gap:10px;align-items:flex-start;background:#f8fbff}.principle b{white-space:nowrap;color:#1d4ed8}.principle span{color:#334155;line-height:1.75}.pulse-box{border-color:#bfdbfe;background:linear-gradient(180deg,#eff6ff,#fff);color:#1e3a8a;line-height:1.8;font-weight:650}@media(max-width:720px){.principle{display:block}.principle b{display:block;margin-bottom:6px}}